Prodel Eliza, Gondim Maitê L, Rocha Helena N M, Mira Pedro A C, Nobrega Antonio C L
Laboratory of Exercise Science, Department of Physiology and Pharmacology, Fluminense Federal University, Rio de Janeiro, Niteroi, Brazil.
National Institute for Science & Technology-INCT (In)Activity & Exercise, Rio de Janeiro, Niteroi, Brazil.
Clin Auton Res. 2022 Aug;32(4):261-269. doi: 10.1007/s10286-022-00879-w. Epub 2022 Jul 23.
We investigate the impact of menopause on cardiovascular adjustments to the cold pressor test (CPT) and the role of the α1-adrenergic receptor.
Ten young women (YW) and nine postmenopausal women (MW) underwent 1 min of CPT in control and α1-blockade conditions (0.03 mg‧kg of oral prazosin).
CPT increased heart rate (HR) (YW: ∆20 ± 3 bpm; MW: ∆13 ± 2 bpm) and stroke volume (SV; YW: ∆15 ± 8 ml; MW: ∆9 ± 6 ml; p = 0.01 for time) and evoked a greater increase in cardiac output (CO) in YW (YW: ∆2.1 ± 0.2 l‧m; MW: ∆1.3 ± 0.5 l‧m; p = 0.01). α1-Blockade increased baseline HR and did not change HR, SV, and CO responses to CPT. MW presented an exaggerated systolic blood pressure (BP) response (YW: ∆38 ± 9 mmHg; MW: ∆56 ± 24 mmHg; p = 0.03). The α1-blockade did not change baseline BP while blunting its response. Total vascular resistance (TVR) was similar between groups at baseline and increased during CPT only in MW (YW: ∆2.3 ± 1.4 mmHg‧L‧min; MW:∆6.8 ± 5.9 mmHg‧L‧min). Under α1-blockade, the TVR increase during CPT was attenuated in MW and abolished in YW (YW: ∆0.3 ± 1.2 mmHg‧L‧min and MW: ∆3.0 ± 2.0 mmHg‧L‧min). CPT did not change femoral vascular conductance (FVC) in either group before the blockade (YW: ∆-0.3 ± 4.0 ml‧min‧mmHg; MW: ∆-0.2 ± 0.8 ml‧min‧mmHg); however, FVC tended to increase in young women (YW: ∆1.3 ± 1.0 ml‧min‧mmHg; MW: ∆0.1 ± 1.5 ml‧min‧mmHg; p = 0.06) after the α1-blockade.
In postmenopausal women, the cardiac ability to adjust to CPT is blunted and α1-adrenergic receptor stimulation is important for the increase in stroke volume. In addition, the peripheral effect of α1-adrenergic receptor stimulation seems to be increased in postmenopausal women.
我们研究绝经对心血管系统对冷加压试验（CPT）反应的影响以及α1 - 肾上腺素能受体的作用。
10名年轻女性（YW）和9名绝经后女性（MW）在对照和α1 - 受体阻断条件下（口服哌唑嗪0.03mg·kg）进行1分钟的CPT。
CPT使心率（HR）增加（YW：Δ20±3次/分钟；MW：Δ13±2次/分钟）和每搏输出量（SV；YW：Δ15±8ml；MW：Δ9±6ml；时间因素p = 0.01），并且YW的心输出量（CO）增加幅度更大（YW：Δ2.1±0.2l·m；MW：Δ1.3±0.5l·m；p = 0.01）。α1 - 受体阻断增加了基础心率，并且不改变对CPT的HR、SV和CO反应。MW表现出夸张的收缩压（BP）反应（YW：Δ38±9mmHg；MW：Δ56±24mmHg；p = 0.03）。α1 - 受体阻断不改变基础BP，但减弱其反应。两组在基线时总血管阻力（TVR）相似，仅在MW中CPT期间增加（YW：Δ2.3±1.4mmHg·L·min；MW：Δ6.8±5.9mmHg·L·min）。在α1 - 受体阻断下，MW中CPT期间TVR的增加减弱，而YW中则被消除（YW：Δ0.3±1.2mmHg·L·min和MW：Δ3.0±2.0mmHg·L·min）。在阻断前，CPT在两组中均未改变股血管传导（FVC）（YW：Δ - 0.3±4.0ml·min·mmHg；MW：Δ - 0.2±0.8ml·min·mmHg）；然而，在α1 - 受体阻断后，年轻女性的FVC有增加趋势（YW：Δ1.3±1.0ml·min·mmHg；MW：Δ0.1±1.5ml·min·mmHg；p = 0.06）。
在绝经后女性中，心脏对CPT的调节能力减弱，α1 - 肾上腺素能受体刺激对每搏输出量增加很重要。此外，绝经后女性中α1 - 肾上腺素能受体刺激的外周效应似乎增强。
